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Fungal exopolysaccharides (EPSs) are natural biopolymers with diverse potential applications in the biomedical, packaging, cosmetic, and food industries. Fungal EPSs are easy to extract and purify polysaccharides that are biodegradable, biocompatible, with low immunogenicity, bioadhesion ability, antibacterial activity, and contain different reactive groups such as hydroxyl, carboxyl, and amine for chemical modifications. Despite fast progress in identifying and characterization fungal EPSs for biomedical applications, i.e., wound healing, drug, and gene delivery, only a few products have been commercialized based on fungal EPSs. This review critically discusses potential biomedical applications of fungi sourced EPSs in tissue engineering (TE), drug and gene delivery., (Copyright © 2021. Published by Elsevier Ltd.)

Alginate biopolymers are characterized by favorable properties, of biocompatibility, degradability, and non-toxicity. However, the poor stability properties of alginate have limited its suitability for diverse applications. Recently, click chemistry has generated significant research interest due to its high reaction efficiency, high selectivity for a single product, harmless byproducts, and processing simplicity. Alginate modified using click chemistry enables the production of alginate derivatives with enhanced physical and chemical properties. Herein, we review the employment of click chemistry in the development of alginate-based materials or systems. Various click chemistries were highlighted, including azide and alkyne cycloaddition (e.g. Copper-(I)-catalyzed azide-alkyne cycloaddition (CuAAC), Strain-promoted alkyne-azide cycloaddition (SPAAC)), Diels-Alder reaction (Inverse electron demand Diels-Alder (IEDDA) cycloaddition, Tetrazine-norbornene Diels-Alder reactions), Thiol-ene/yne addition (Free-radical thiol-ene addition click reactions, Thiol-Michael addition click reactions, Thiol-yne addition click reaction), Oxime based click reactions, and other click reactions. Alginate functionalized with click chemistry and its properties were also discussed. The present study shows that click chemistry may be employed in modifying the mechanical strength, biochemical/biological properties of alginate-based materials. Finally, the applications of alginate-based materials in wound dressing, drug delivery, protein delivery, tissue regeneration, and 3D bioprinting were described and the future perspectives of alginates modified with click chemistry, are subsequently presented. This review provides new insights for readers to design structures and expand applications of alginate using click chemistry reactions in a detailed and more rational manner., (Copyright © 2021 Elsevier Ltd. All rights reserved.)